A method of drying a hand and an apparatus for hand drying as outlined above are known from WO 2007/015043 A1. The known apparatus for hand drying comprises a hand insertion opening with two merged opening areas which are each provided for one hand and which are arranged side by side. A distance of the longitudinal sides of the hand insertion opening is 70 to 100 mm, i.e. about 85 mm, and this distance is reduced at both ends of the hand insertion opening and between its two opening areas to 50 to 80 mm, i.e. about 65 mm. At both longitudinal sides of the hand insertion opening, slot nozzles are arranged which are connected to a blower in the housing of the apparatus to blow planar gas jets out of the slot nozzles. The gas jets consist of air whose velocity is at least 80 m/s, preferably at last 100 or 150 m/s, more preferably about 180 m/s. Besides the hand insertion opening, the housing of the known apparatus has big lateral openings directly connected to the hand insertion opening, through which the blown out air of the gas jets passes into the surroundings of the apparatus. In this way, however, water blown away from the hands and germs blown away from the hands together with the water are delivered into the surroundings of the apparatus. The air which is sucked in by the blower for blowing it out of the slot nozzles is sucked in through a filter.
The angle between the planar gas jets emerging out of the slot nozzles by which the palmar aspect and the dorsal aspect of the respective hand are blown off is an obtuse angle, i.e. the slot nozzles are directed into the housing of the apparatus at a small slant angle only.
A further development of the apparatus for hand drying known from WO 2007/015043 A1 is disclosed in WO 2014/091191 A1. Here, the slot nozzles are oriented into the housing at a higher slant angle. The slant angle of the one slot nozzle is constant, whereas the slant angle of the opposing slot nozzle varies over the width of the hand insertion opening particularly in a range from 50° to 59° with regard to a horizontal plane of the hand insertion opening.
EP 2 223 704 A1 discloses a treatment apparatus for treating a body part of a patient with a non-thermal plasma. The apparatus is particularly intended for sterilizing a hand of a human. The apparatus has a housing for temporarily receiving the body part during the treatment and for applying a plasma to the body part within the housing. The housing has an insertion opening for inserting the body part into the housing. The housing further includes a plasma generator, a high voltage generator, an outer electrical insulation, a gas-permeable radiation shielding and a spacer. The plasma generator has two essentially planar arrangements for generating a dielectric barrier discharge. The one arrangement is arranged above, the other arrangement is arranged below a treatment area. Both arrangements have two electrodes and a dielectric barrier between the electrodes. By applying an alternating high voltage provided by the high voltage generator between the two electrodes, a dielectric barrier discharge is ignited which emits ultraviolet radiation.
JP 4 796 281 B2 discloses an apparatus for disinfection by means of a hot plasma jet. A dielectric barrier discharge is ignited in an air jet generated by a blower. The discharge also generates the desired heat of the hot plasma jet.
U.S. Pat. No. 8,607,472 B2 discloses an apparatus for hand drying in which an ion generator enriches air jets emerging out of slot nozzles with ions which have a sterilizing effect. In this known apparatus, water blown away from the hands is collected, and a part of the air blown out of the slot nozzles is once again sucked in by a blower connected to the slot nozzles and thus circulated. The ion generator generates the ions by means of a corona discharge between two electrodes which are arranged upstream of the slot nozzles.
EP 2 656 762 A2 (corresponding to US 2013/0283629 A1) discloses an apparatus for drying hands comprising a housing in which a cavity accessible from the outside is formed for receiving the hands to be dried by means of an airflow. Further, a blower for generating the airflow and means for reducing germs in the airflow are arranged in the housing. These means for reducing the germs may be a device for supplying a germ-reducing substance to the airflow, a plasma or ion source and/or a radiation source. The plasma or ion source may be a microwave or high frequency plasma or ion source. The radiation source may be a UV radiator or a dielectric barrier discharge lamp. The known apparatus may further have an air outlet conduit and an air inlet conduit communicating with the cavity in such a way that the airflow may be circulated through the air outlet conduit and the air inlet conduit as well as the cavity. The means for reducing the germs are particularly arranged in the area of the air outlet conduit. They may, however, also be arranged in the cavity, if they are radiation sources, for example.
CN 103 876 678 A discloses an apparatus for hand drying comprising a blower, a heating wire, an electrode plate and an alternating voltage source. The blower generates a warm airflow onto the electrode plate by means of the heating wire. When a wet washed hand is stretched out on the electrode plate, discharges occur with regard to the wet surface of the hand. These discharges kill germs on the surface of the hand and remove water. Together with the warm airflow, the hand is dried quickly. The alternating voltage source provides an alternating voltage between the electrode plate and a grid, an isolator plate being arranged in between. The grid is facing the and the blower arranged upstream of the heating wire. It is not disclosed how in this arrangement a discharge for generating a plasma may be generated by means of the alternating voltage source with regard to the wet hand which has to be arranged on the grid to be subjected to the warm airflow.
JP 2013-244248 A discloses an apparatus for hand drying having a housing with a hand insertion opening. The hand insertion opening leads between nozzle plates with a plurality of nozzles which are oriented into the housing at a slant angle to blow off the hand inserted into the housing. On the backsides of the nozzle plates facing away from the hand, pairs of electrode plates are provided which have through-openings corresponding to the nozzles in the nozzle plates. At its opposing surfaces, the two electrode plates of each pair are provided with a dielectric coating. By applying an alternating voltage between the two electrodes, a plasma is ignited in air which is supplied by a blower before the air is blown out through the nozzle plates onto the hand.
There still is a need of a method of drying a hand and an apparatus for hand drying which efficiently kill germs on the surface of the hand and which efficiently avoid that germs from the hand are distributed into the surroundings.